Material throwing impellers having pivoting paddles are used in silo unloaders to pick up silage and haylage and throw these materials into a silage chute. An example of a impeller for a silo unloader having a pivoted paddles is shown by Hansen in U.S. Pat. No. 3,589,500. The paddles have generally V-shaped metal bodies pivotally connected to a rotor mounted on a drive shaft. The paddles are rotated within a housing having a bottom entrance opening and a top exit opening. The paddles move in close relationship to a sheet metal back wall leading upwardly to the exit opening. The paddles as they pick up the material impact material on the back wall and other inside surfaces of the housing. The material being wet has gum and strong adhessive characteristics which causes the material to collect on the back wall of the housing. The build up of a material on the back wall interfers with the rotational movement of the paddles and increases the power required for rotating the impeller. The build up of the gum-like material on the housing and paddles also decreases the throwing ability of the paddles. The material must be periodically removed from the interior of the housing which is a difficult and time consuming task. It is common practice to wash the inside of the impeller housing and impeller paddles with water to remove the material collected on the metal surfaces of the housing and impeller paddles. The machine must be shut down and manually serviced. A water hose must be hauled up into the silo so that the operator can flush out the machine to remove build up of material from the operating parts thereof. The impeller housing and paddles of the invention have substantially reduced material collection problems and eliminated the need to wash the machine to maintain efficient operation.
Silo unloader impeller housings are fabricated sheet metal structures having material inlet and outlet openings. An impeller having pivoted paddles is located within the housing. An example of a one-piece silo unloader impeller housing is disclosed by F. E. Buschbom in U.S. Pat. No. 3,221,904 issued Dec. 7, 1965. This housing cannot be taken apart to service and clean the interior thereof. Silo unloader impeller housings have been made in two sections to aid in assembly of the housings. These housings have a top section having horizontal members secured to a bottom section generally along the horizontal plane of the axis of rotation of the impeller. Major parts of the silo unloader must be removed to take the housing apart. This is a substantial project and is not normally done to clean out the impeller housing and impeller therein. The impeller apparatus of the invention has overcome these disadvantages of the prior silo unloader impeller housings.